Threaded connections are a common structure used in fastening two objects together. External or threads are typically found on, for example, male components, such as a bolt, screw or on pipes. These threads either engage a working material directly, such as a board of wood and grip the wood directly to fasten the wood to another object, or a corresponding female component that has threads, such as a threaded coupling or nut. With a threaded connection, the threads of the male component cooperatively engage the threads of the female component by relative rotation. In both circumstances, and with threads in general, rotation of the male or female components relative to each other results in coupling and tightening of the threaded connection, or decoupling and loosening of the thread, depending on the direction of rotation. Typically, clockwise rotation causes tightening, and counterclockwise rotation causes loosening.
During use, and especially over time, threads of either the male or female components can become damaged, such as being “stripped” and therefore difficult or impossible to use as intended. For example, threads of the female component can become warped by inexact fittings of threads of the male component. Once damaged, the threads of the male and female components cannot matingly engage, and thus do not either tighten or loosen.
Thread chases or taps exist for repairing damaged threads of female components. Thread chases typically involve a device having teeth or other cutting elements that are inserted into the female component and is then rotated to cut into the thread material, such as, for example, a metal, to regain the structure of the threads and thus repair the threads. However, many thread chases are inserted into the female component and begin at the outermost damaged threads, and rotate until they are within the undamaged threads. Typically, this is done with clockwise rotation, as with a tap. However, positioning the tap in this fashion can become difficult because the initial threads are often damaged, thus leading to misalignment, and are therefore more difficult to insert the thread chase into and thus create a proper realignment of the threads.
Other thread chases allow the cutting members to insert past the damaged threads to undamaged, engage the undamaged threads for alignment, and then retract backwards (such as counterclockwise) to chase the threads that were damaged. However, such thread chases are often difficult to push past the undamaged threads due to their bulky nature and outward cutting surfaces. These thread chases can also damage the undamaged threads during insertion unless the thread chase is thin and can move within the opening without abutting the threads until so desired.